(a) Field of the Invention
The present invention relates to an apparatus and method for packet-optical integrated transport performing integrated switching of a multi-layer packet and an optical signal by a single system in wire/wireless environment.
(b) Description of the Related Art
A general packet-optical transport network has an overlay structure in which there are mixed a packet-based router network (e.g. IP/Ethernet) and a circuit-based transport network (e.g. a synchronous optical network/synchronous digital hierarchy (SONET/SDH), a wavelength division multiplexing (WDM)), which is complicated since apparatus for individual functional layers are scattered and managed.
The packet-based router network has a structure performing unnecessary multi-hop routing even though more than half of transport network traffic has a traffic transition characteristic, which degrades the quality of multimedia-service-based premium traffic. Further, in order to expand the network, it needs an expensive large-capacity router.
Network traffic of the circuit-based transport network becomes IP-packet-centric from time division multiplexer (TDM)-circuit-centric because of rapid development of the Internet field. However, the circuit-based transport network has an inefficient structure to transport IP traffic increasing as composed to TDM traffic and needs a dedicated circuit having an expansive structure having a low degree of wire integration, and long standby time for new services.
Communication service providers continuously expand existing networks and implement new networks in order to accommodate a continuous increase of Internet traffic caused by wire/wireless services developing to a triple play service (TPS) (e.g., VoIP, IPTV, Managed Internet, etc.), a quadruple play service (QPS) (e.g., TPS+3G/WiMAX/LTE, etc.). However, it is very inefficient in terms of installation investment costs and operation/administration/maintenance costs such as complexity of infrastructure expansion, operation and management, an increase of power consumption, complexity of interlayer network resource control, and complexity of network resource assignment.
For these reasons, various additional techniques are being discussed in order to the above-mentioned problems in companies associated with the packet-based router network and the circuit-based transport network. However, the individual techniques have technical limits. Therefore, in order to overcome the technical limits, network development is required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.